(why do my) wet brakes???? (perform poorly)

[landcrusier ute]

when ever i drive through a mud or water hole i have no brkae pedal for a while
and then after that my pedal is really spoongy why is this when i have disc all way round?????

[MART]

Cause you cool the rotor instantly , they shrink slightly making pads loose , once they heat up again they come good again , Cheers Paul.

[Peter @ Aawen4x4]

Probly worse if you've been working the discs hard, and it'll appear worse for discs than it will for drums!

[Bumpy]

Cause you cool the rotor instantly , they shrink slightly making pads loose , once they heat up again they come good again , Cheers Paul.

Doesn't make sense, I can accept that the roror will shrink but that would mean that the piston has to travel a bit further, which means that the pedal would have to travel a bit further as well. If this is what LCR ute means by spongy then fine, but the pedal should still be firm. Could be the water flashing off as steam seperates the rotor and pad thus loosing the positive feel.
Just a thought.

[HDJ105]

when ever i drive through a mud or water hole i have no brkae pedal for a while
and then after that my pedal is really spoongy why is this when i have disc all way round?????

Water works as a lubricant between the pad and disc. I've found slotted rotors do reduce this effect somewhat.

Do you have drums or discs on the rear? Wet drums are well known for their lack of effect, particularly going backwards.

PS. Perhaps next time you could add another 2 words to the title?

[lux2.8]

hey i did a bit of water and mud driving the other day the brakes are not performing as well now any suggestions are they just a bit dirty ??

[MART]

Got rear drums , rear shoes might be buggered , I don't go near mud or water , it costs toooo much money , sand/mud acts like sandpaper and grinds the shoes away , is the pedal spongy or low , that be ya problem , Cheers Paul.

[overit]

Ive found if you ride the brakes for bit after driving through water or mud gets em working again. Ive got disc front and drum rear in a 92 4runner.

[mark4130]

This is just a theory but could the sudden cooling of the rotor be causing a slight hardening effect upon both the rotor and pads similar to having glazed pads?
And thats why they become better after they have deglazed!
I think its just something we need to be aware of and comensate for unfortunatly.

Mark

[big ben]

2 part reason. After water the pads cool down out of their temp. range, and because you are 4x4ing and moving very slowly, you are not getting heat back into the pads/disc. You may notice on a cold morning the first brake application, the brakes dont have great bite, well the pads are below their optimim temprature range. It behaves like a high temp brake fade .
So your brakes are out of temp range and now you have added a lubricant which is the water.... then you drive into the next boghole....